Réaction #2006439

Équation de réaction

hydrogen

cyclopentadiene

cyclopentadiene

bromine

hydrogen peroxide

NaOH

bromine

→

alcohol

1-Cyclopentylcyclopentanol

Solvants

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

methanol

Conditions de réaction

Traitement

1. 1
   AutreTo a 1000-mL 3-necked round bottom flask equipped with a 250-mL pressure
2. 2
   workup.ADDITIONaddition funnel, a nitrogen inlet with thermocouple and an overhead stirrer
3. 3
   AutreThe flask was immersed in an ice-water bath
4. 4
   AutreThe solvent was then removed under reduced pressure
5. 5
   Autrethe remaining oil transferred to a 5 L 3-necked round bottom flask
6. 6
   Autreequipped with a thermocouple inlet
7. 7
   workup.ADDITIONoverhead stirrer and a 500-mL addition funnel
8. 8
   workup.ADDITIONDichloromethane (2 L) and water (500 mL) were added
9. 9
   workup.ADDITIONwas then added slowly over 1 hr
10. 10
    Autrewas recooled to 5° C.
11. 11
    workup.STIRRINGAfter stirring overnight at room temperature the organic layer
12. 12
    Autrewas separated
13. 13
    Lavagewashed several times with water
14. 14
    Séchageonce with brine and then dried over anhydrous magnesium sulfate for 1 hour
15. 15
    FiltrationFiltration and removal of the solvent at reduced pressure
16. 16
    Autreresulted in a light-colored oil which
17. 17
    workup.DISTILLATIONwas distilled from Na2CO3 through a short Vigreux (bp 63° C.@ 1 mmHg)

Mode opératoire

To a 1000-mL 3-necked round bottom flask equipped with a 250-mL pressure equalizing addition funnel, a nitrogen inlet with thermocouple and an overhead stirrer was added 172 mL (1.72 mol) of a 10M solution of BH3-Me2S in tetrahydrofuran and 300 mL of dry tetrahydrofuran. The addition funnel was charged with 116.8 g (1.72 mol) of cyclopentadiene dissolved in 100 mL of dry tetrahydrofuran. The flask was immersed in an ice-water bath and the cyclopentadiene solution slowly added over 2 hours at 0-5° C. Stirring was continued for an additional 90 min at this temperature at which time 130 mL of methanol was cautiously added over 1 hour with vigorous evolution of hydrogen. The solvent was then removed under reduced pressure and the remaining oil transferred to a 5 L 3-necked round bottom flask equipped with a thermocouple inlet, overhead stirrer and a 500-mL addition funnel. Dichloromethane (2 L) and water (500 mL) were added and the mixture cooled to 5° C. The addition funnel was charged with 100 mL (1.95 mol) of bromine which was then added slowly over 1 hr. The resulting dark mixture was exposed to a long wave UV lamp with stifling at room temperature overnight by which time the bromine color had largely disappeared. The reaction mixture was recooled to 5° C. and 1.3 L of 6N NaOH was added slowly via the addition funnel followed by 400 mL of 30% hydrogen peroxide. After stirring overnight at room temperature the organic layer was separated, washed several times with water, once with brine and then dried over anhydrous magnesium sulfate for 1 hour. Filtration and removal of the solvent at reduced pressure resulted in a light-colored oil which was distilled from Na2CO3 through a short Vigreux (bp 63° C.@ 1 mmHg) to yield 72 g (55%) the title alcohol as a clear, colorless oil.

Source